This invention is in the field of sewing machines; more particularly, it is concerned with a mechanism supportable on a sewing machine bed for the purpose of moving a work material for continuous stitching thereon of words, patterns or monograms.
Prior art devices for monogramming or continuous patterning have been limited by the bight capability of the sewing machine. Thus, for example, in the Japanese Patent Publication No. 49578/74 (Dec. 27. 1974--Takatomi) there is shown a device which may be operated by the needle bar of the sewing machine to feed a work material beneath a sewing needle in order to generate a continuous pattern having a width equal to the bight capability of the sewing machine.
In other prior art devices, a form of an embroidery hoop is utilized to support the work material beneath the sewing machine, and move the work material in the formation of larger patterns or writings. Such devices are shown in the U.S. Pat. Nos. 4,195,581 and 3,734,038 of O'Hara and Takatomi, respectively.
There is also the commonly assigned U.S. patent application Ser. No. 211,098 of D. R. Davidson, filed Dec. 29, 1980. That application discloses a continuous monogrammer utilizing a first frame to carry a pair of spaced apart belts driven by stepper motors to transport a wide band of work material laterally beneath a sewing machine needle. A second stepper motor carried by a second frame attached to the sewing machine presser bar rotates a gear in mesh with a worm carried by the belt frame to cause the belts and work material transported thereby to move in a longitudinal direction beneath the sewing machine needle in the formation of monograms, patterns, or words having a height equal to the depth of the work material. However, the prior art device utilized two separate frames which created some difficulty while using the machine, especially in attempting fabric repositioning. Further, fabric control during stitching was somewhat of a problem because of the large unsupported distance between the driving belts.
What is required is a one-piece monogrammer which will exert a substantial degree of control over the work material being transported thereby.